Method for operating a hybrid commutation converter valve and hybrid commutation converter valve

Abstract

The application relates to a hybrid commutation valve operation method and a hybrid commutation valve. The method comprises the following steps: acquiring phase current measurement values of an AC inlet of the hybrid commutation valve, and acquiring bridge arm conduction state information of the hybrid commutation valve; combining preset corresponding relationships among the bridge arm conduction state, the phase current and the bridge arm current; and analyzing and calculating the bridge arm current of a current conduction bridge arm. According to the scheme, the bridge arm current of the hybrid commutation valve is indirectly obtained by measuring the phase current measurement values of the AC inlet of the hybrid commutation valve and analyzing in combination with the bridge arm conduction state information, the current sensor does not need to be installed on the bridge arm of the hybrid commutation valve, the accuracy of the obtained bridge arm current is ensured, and the accuracy of the bridge arm current is high. Therefore, the active shutdown monitoring of the hybrid commutation valve is realized by using the bridge arm current with high accuracy, and the operation reliability of the hybrid commutation valve is effectively improved.

Description

Technical Field

[0001] This application relates to the field of converter technology, and in particular to a method for operating a hybrid commutation converter valve and the hybrid commutation converter valve itself. Background Technology

[0002] With the development of power technology, hybrid commutation converter valves with active commutation function are gradually being used in high-voltage direct current transmission systems. Hybrid commutation converter valves generally use IGCT (Integrated Gate Commutated Thyristor) as the active turn-off module. During operation, it is usually necessary to determine whether active turn-off is required based on the arm current. During active turn-off, it is necessary to further determine whether overcurrent turn-off is required based on the arm current. Therefore, detecting the arm current flowing through the arm is of great significance for the reliable operation of hybrid commutation converter valves.

[0003] However, in related technologies, due to the complex internal electromagnetic environment and strong vibration of the hybrid commutation valve, it is usually difficult to install a current sensor at the bridge arm of the hybrid commutation valve to collect accurate bridge arm current, resulting in poor operational reliability of the hybrid commutation valve. Summary of the Invention

[0004] Therefore, it is necessary to provide a hybrid commutation converter valve operation method and a hybrid commutation converter valve to obtain accurate bridge arm current, thereby improving the operational reliability of the hybrid commutation converter valve.

[0005] A method for operating a hybrid commutator valve includes: acquiring bridge arm conduction status information of the hybrid commutator valve; acquiring a phase current measurement value at the AC inlet of the hybrid commutator valve; determining the bridge arm current of the currently conducting bridge arm based on the bridge arm conduction status information, the phase current measurement value, and a preset correspondence between bridge arm conduction status, phase current, and bridge arm current; wherein the bridge arm current is used for active shutdown monitoring of the hybrid commutator valve.

[0006] In one embodiment, the hybrid commutator valve operation method further includes: acquiring a DC current measurement value at the DC input port of the hybrid commutator valve; and performing fault detection on the hybrid commutator valve based on the DC current measurement value and the phase current measurement value.

[0007] In one embodiment, the DC current measurement values ​​include a first-terminal DC current measurement value and a second-terminal DC current measurement value, and the phase current measurement values ​​include Y-bridge phase current measurement values ​​and D-bridge phase current measurement values; the fault detection of the hybrid commutation converter valve based on the DC current measurement values ​​and the phase current measurement values ​​includes: determining the first phase current maximum value based on the absolute value of the D-bridge phase current measurement value; determining the second phase current maximum value based on the absolute value of the Y-bridge phase current measurement value; and performing fault detection of the hybrid commutation converter valve based on the first phase current maximum value, the second phase current maximum value, the first-terminal DC current measurement value, and the second-terminal DC current measurement value.

[0008] In one embodiment, the fault detection of the hybrid commutator valve based on the maximum value of the first phase current, the maximum value of the second phase current, the measured value of the first terminal DC current, and the measured value of the second terminal DC current includes: determining a first criterion condition based on the maximum value of the first phase current, the measured value of the first terminal DC current, and a predetermined starting current value; determining a second criterion condition based on the maximum value of the first phase current, the maximum value of the second phase current, and the predetermined starting current value; determining a third criterion condition based on the maximum value of the second phase current, the measured value of the second terminal DC current, and the predetermined starting current value; and performing fault detection on the hybrid commutator valve based on the first criterion condition, the second criterion condition, and the third criterion condition.

[0009] In one embodiment, the fault detection of the hybrid commutation valve based on the first criterion, the second criterion, and the third criterion includes: determining the fault state of the hybrid commutation valve based on the number of triggering criteria and the triggering method among the first criterion, the second criterion, and the third criterion.

[0010] In one embodiment, determining the fault state of the hybrid commutator valve based on the number of triggering criteria and the triggering method among the first, second, and third criteria includes: when the number of triggering criteria among the first, second, and third criteria is one in a cycle, determining the ground fault type of the hybrid commutator valve according to the triggering method; and when the number of triggering criteria among the first, second, and third criteria is two in a cycle, determining the short-circuit fault type of the hybrid commutator valve according to the triggering method.

[0011] In one embodiment, the hybrid commutator valve operation method includes at least one of the following: a first criterion, wherein the absolute value of the difference between the maximum value of the first phase current and the measured value of the first terminal DC current is greater than the set value of the starting current; a second criterion, wherein the absolute value of the difference between the maximum value of the first phase current and the maximum value of the second phase current is greater than the set value of the starting current; and a third criterion, wherein the absolute value of the difference between the maximum value of the second phase current and the measured value of the second terminal DC current is greater than the set value of the starting current.

[0012] In one embodiment, obtaining the phase current measurement value of the AC inlet of the hybrid commutator valve includes: receiving current sampling values ​​collected and transmitted by a phase current acquisition device disposed at the AC inlet of the hybrid commutator valve; wherein, one phase current acquisition device is disposed corresponding to one AC inlet, each phase current acquisition device includes at least two fiber optic current transformers, and each fiber optic current transformer acquires a current sampling value; and performing optimization analysis based on each current sampling value to determine the phase current measurement value of the AC inlet.

[0013] In one embodiment, the step of performing optimal analysis based on the current sampling values ​​to determine the phase current measurement value of the AC input port includes: verifying whether each of the current sampling values ​​is abnormal; and determining the phase current measurement value of the AC input port based on the normal current sampling values ​​when at least two of the current sampling values ​​are normal.

[0014] In one embodiment, determining the phase current measurement value of the AC input port based on the normal current sampling values ​​when at least two of the current sampling values ​​are normal includes: when two of the current sampling values ​​are normal, taking the average of the two normal current sampling values ​​as the phase current measurement value of the AC input port; when three or more of the current sampling values ​​are normal, determining the average of the normal current sampling values, and taking the normal current sampling value with the smallest absolute value of the difference from the average value as the phase current measurement value of the AC input port.

[0015] In one embodiment, before receiving the current sampling value collected and transmitted by the phase current acquisition device located at the AC inlet of the hybrid commutation valve, the method further includes: acquiring the operating status of each of the fiber optic current transformers in the phase current acquisition device; performing the step of receiving the current sampling value collected and transmitted by the phase current acquisition device located at the AC inlet of the hybrid commutation valve when at least two of the fiber optic current transformers are normal; and outputting a prohibition on active shutdown prompt message when all of the fiber optic current transformers are abnormal or one of the fiber optic current transformers is normal.

[0016] A hybrid phase-commutation converter valve includes a bridge arm power unit, a phase current acquisition device, and a control device. The phase current acquisition device is disposed at the AC input port of the bridge arm power unit. The phase current acquisition device and the bridge arm power unit are respectively connected to the control device. The control device is used to execute the steps of the above-described hybrid phase-commutation converter valve operation method.

[0017] In one embodiment, a DC current acquisition device is also included, which is disposed at the DC input port of the bridge arm power unit and is connected to the control device.

[0018] In one embodiment, the phase current acquisition device and the DC current acquisition device have the same structure, both including at least two fiber optic current transformers.

[0019] In one embodiment, the control device includes a valve controller, and a first active shutdown judgment chassis and a second active shutdown judgment chassis that are redundant with each other. The phase current acquisition device is connected to the first active shutdown judgment chassis and the second active shutdown judgment chassis respectively, and the first active shutdown judgment chassis and the second active shutdown judgment chassis are connected to the valve controller respectively.

[0020] The aforementioned hybrid commutator valve operation method and valve itself, by acquiring the phase current measurement value at the AC inlet of the hybrid commutator valve and the bridge arm conduction status information, and combining this with a preset correspondence between bridge arm conduction status, phase current, and bridge arm current, calculates the bridge arm current of the currently conducting bridge arm. This scheme indirectly obtains the bridge arm current of the hybrid commutator valve by measuring the phase current measurement value at the AC inlet of the hybrid commutator valve and analyzing it in conjunction with the bridge arm conduction status information. This eliminates the need to install current sensors on the bridge arms of the hybrid commutator valve, is unaffected by electromagnetic interference or vibration, and ensures the accuracy of the acquired bridge arm current. Thus, by using the highly accurate bridge arm current to achieve active shutdown monitoring of the hybrid commutator valve, the operational reliability of the hybrid commutator valve is effectively improved. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of this application or the conventional technology, the drawings used in the description of the embodiments or the conventional technology will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 This is a schematic diagram of the operation method of the hybrid commutation valve in one embodiment of this application;

[0023] Figure 2 This is a schematic diagram of the hybrid commutation valve topology in one embodiment of this application;

[0024] Figure 3 This is a schematic diagram of the operation method of the hybrid commutation valve in another embodiment of this application;

[0025] Figure 4 This is a schematic diagram of the operation method of the hybrid commutation valve in another embodiment of this application;

[0026] Figure 5 This is a schematic diagram of the fault detection process for a hybrid commutation converter valve in one embodiment of this application;

[0027] Figure 6 This is a schematic diagram of the fault detection process for the hybrid commutation valve in another embodiment of this application;

[0028] Figure 7 This is a schematic diagram of the process for determining the phase current measurement value in one embodiment of this application;

[0029] Figure 8 This is a schematic diagram of the process for determining the phase current measurement value in another embodiment of this application;

[0030] Figure 9 This is a schematic diagram of the process for determining the phase current measurement value in another embodiment of this application;

[0031] Figure 10 This is a schematic diagram of the process for determining phase current measurement values ​​in another embodiment of this application;

[0032] Figure 11 This is a schematic diagram of the hybrid commutation valve topology in another embodiment of this application. Detailed Implementation

[0033] To facilitate understanding of this application, a more complete description will be provided below with reference to the accompanying drawings. Preferred embodiments of this application are shown in the drawings. However, this application can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a thorough and complete understanding of the disclosure of this application.

[0034] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

[0035] It is understood that the terms "first," "second," etc., used herein may be used to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish one element from another. For example, without departing from the scope of this application, a first resistor may be referred to as a second resistor, and similarly, a second resistor may be referred to as a first resistor. Both the first resistor and the second resistor are resistors, but they are not the same resistor.

[0036] It is understood that the term "connection" in the following embodiments should be understood as "electrical connection," "communication connection," etc., if the connected circuits, modules, units, etc., have electrical signal or data transmission with each other.

[0037] It is understandable that "at least one" refers to one or more, and "multiple" refers to two or more. "At least a part of an element" refers to part or all of an element.

[0038] When used herein, the singular forms of “a,” “an,” and “the” may also include the plural forms unless the context clearly indicates otherwise. It should also be understood that the terms “comprising / including” or “having,” etc., specify the presence of the stated features, wholes, steps, operations, components, parts, or combinations thereof, but do not preclude the possibility of the presence or addition of one or more other features, wholes, steps, operations, components, parts, or combinations thereof. Meanwhile, the term “and / or” as used in this specification includes any and all combinations of the associated listed items.

[0039] The hybrid commutation converter valve operation method provided in this application is applied to a current source converter valve with hybrid commutation function (i.e., capable of both natural and active commutation). Its detailed structure is not unique and is not specifically limited. To facilitate understanding of the technical solution of this application, the following embodiments all use a 12-pulse converter valve as an example for explanation and illustration.

[0040] Please see Figure 1 A method for operating a hybrid commutation valve includes steps 102, 104, and 106.

[0041] Step 102: Obtain the bridge arm conduction status information of the hybrid commutation valve.

[0042] Specifically, the bridge arm conduction status information is used to characterize the bridge arms in the hybrid commutation valve that are in the conduction state. In the embodiments of this application, the hybrid commutation valve is equipped with a control device. The control device can acquire various state parameters during the operation of the hybrid commutation valve and send on / off control signals to the bridge arm power units of the hybrid commutation valve based on these state parameters, thereby realizing the commutation function. Therefore, through the control device, information related to the conduction of the bridge arms of the hybrid commutation valve can be retrieved, thereby obtaining the bridge arm conduction status information.

[0043] It should be noted that the type of bridge arm conduction status information is not unique. In one embodiment, it can be a bridge arm conduction control signal used to control the on / off state of the bridge arm of the hybrid commutation valve. In another embodiment, the bridge arm conduction status information can also be the currently conducting bridge arm number, or the commutation state of the commutation valve, etc., and there is no specific limitation.

[0044] Step 104: Obtain the phase current measurement value at the AC inlet of the hybrid commutation valve.

[0045] Specifically, the AC inlet port, also known as the bridge arm power unit in a hybrid phase-commutation converter valve, is used to connect to the AC side line port. In practice, the number of AC inlets varies depending on the type of hybrid phase-commutation converter valve. For example, with a 12-pulse converter valve, please refer to [link to relevant documentation]. Figure 2 Its bridge arm power units include a Y-bridge (specifically, VY1, VY2, VY3, VY4, VY5, and VY6 as shown in the diagram) and a D-bridge (specifically, VD1, VD2, VD3, VD4, VD5, and VD6 as shown in the diagram). In the Y-bridge, the windings of the converter transformer are typically connected in a Y (star) configuration; while in the D-bridge, the windings of the converter transformer are connected in a D (delta) or Y-Δ (star-delta) configuration. Therefore, the Y-bridge and D-bridge each have three AC input lines. In either the Y-bridge or D-bridge, each AC input line corresponds to phase A, phase B, and phase C, respectively. There are a total of six phase current measurements at the AC input ports, represented as IDA, IDB, IDC, and IYA, IYB, and IYC, respectively. In actual operating conditions, different phase current measurements can be obtained depending on the commutation state of the current hybrid commutation converter valve.

[0046] It should be noted that the method for obtaining phase current measurements is not unique. In one embodiment, a phase current acquisition device can be installed at the inlet of each AC incoming line. This phase current acquisition device is connected to the control device, and it can acquire current sampling values ​​of different phase lines of the D-bridge or Y-bridge. The control device analyzes and processes the received current sampling values ​​to obtain the phase current measurement value. In another embodiment, the control device can directly use the received current sampling value as the phase current measurement value. The specific method can be set according to actual needs.

[0047] It is understood that, in one embodiment, in order to ensure the accuracy of the final phase current measurement value, each phase current acquisition device can sample multiple current sampling values. For each phase line, the control device performs optimization analysis based on the received multiple current sampling values ​​to finally determine the phase current measurement value.

[0048] Step 106: Determine the bridge arm current of the currently conducting bridge arm based on the bridge arm conduction status information, phase current measurement value, and the preset correspondence between bridge arm conduction status, phase current, and bridge arm current.

[0049] Specifically, the bridge arm current is used to monitor the active shutdown of the hybrid commutator valve. Active shutdown monitoring includes, but is not limited to, detecting whether the hybrid commutator valve needs to be activated for active shutdown, and whether overcurrent shutdown occurs during the active shutdown process, etc., without further limitations.

[0050] The control device pre-stores the correspondence between bridge arm conduction status, phase current, and bridge arm current. The bridge arm conduction status includes one or more of the following: bridge arm conduction control signal, the number of the conducting bridge arm, and the converter valve status; the specific type is not limited. In one embodiment, the bridge arm conduction status simultaneously includes the bridge arm conduction control signal, the number of the conducting bridge arm, and the converter valve status. In practical scenarios, only one of these three factors needs to be obtained as the bridge arm conduction status information. This information is then input into the control device along with the phase current measurement value to match and obtain the other two bridge arm conduction statuses, as well as the bridge arm current of the currently conducting bridge arm.

[0051] To facilitate understanding of the technical solution of this application, a 12-pulse converter valve will be used as an example for explanation below. Figure 2As shown, bridge arms VD1 and VD4 are connected, and the common terminal they form serves as the A-phase input terminal of bridge D. The bridge arm currents of both are determined by the phase current measurement value IDA at the input terminal of that phase. Bridge arms VD3 and VD6 are connected, and the common terminal they form serves as the B-phase input terminal of bridge D. The bridge arm currents of both are determined by the phase current measurement value IDB at the input terminal of that phase. Bridge arms VD2 and VD5 are connected, and the common terminal they form serves as the C-phase input terminal of bridge D. The bridge arm currents of both are determined by the phase current measurement value IDC at the input terminal of that phase. The VY1 and VY4 bridge arms are connected, and the common terminal formed is the A-phase input terminal of the Y-bridge. The bridge arm current of both is determined by the phase current measurement value IYA at the phase input terminal. The VY3 and VY6 bridge arms are connected, and the common terminal formed is the B-phase input terminal of the Y-bridge. The bridge arm current of both is determined by the phase current measurement value IYB at the phase input terminal. The VY2 and VY5 bridge arms are connected, and the common terminal formed is the C-phase input terminal of the Y-bridge. The bridge arm current of both is determined by the phase current measurement value IYC at the phase input terminal.

[0052] As shown in the table below, the CP signal, also known as the bridge arm conduction control signal, defines the bridge arm currents corresponding to the six bridge arms VD1, VD2, VD3, VD4, VD5, and VD6 as ID1, ID2, ID3, ID4, ID5, and ID6, respectively; and defines the bridge arm currents corresponding to the six bridge arms VY1, VY2, VY3, VY4, VY5, and VY6 as IY1, IY2, IY3, IY4, IY5, and IY6, respectively.

[0053]

[0054] Taking a CP signal including either VD1 or VD4 as an example, if VD1 is 1 (i.e., VD1 bridge arm is on) and VD4 is 0 (i.e., VD4 bridge arm is not on), the corresponding bridge arm current ID1 flowing through VD1 is negative IDA, and the bridge arm current flowing through VD4 is 0. If VD1 is 0 (i.e., VD1 bridge arm is not on) and VD4 is 1 (i.e., VD4 bridge arm is on), the corresponding bridge arm current ID1 flowing through VD1 is 0, and the bridge arm current flowing through VD4 is IDA. When the CP signals for both VD1 and VD4 are 0, the bridge arm currents flowing through VD1 and VD4 will remain unchanged from the previous CP signal state. For example, if the previous CP signal was VD1=0 and VD4=1, and the current CP signal is VD1=0 and VD4=0, then the correspondence between ID1=0 and ID4=IDA remains unchanged; if the previous CP signal was VD1=1 and VD4=0, and the current CP signal is VD1=0 and VD4=0, then the correspondence between ID1=negativeIDA and ID4=0 remains unchanged.

[0055] It is understandable that when the bridge arm conduction status information is other, according to the correspondence shown in the table above, the bridge arm current value of each bridge arm can be matched with the phase current measurement value at this time, which will not be elaborated here.

[0056] The aforementioned method for operating a hybrid commutator valve obtains the phase current measurement value at the AC inlet of the valve and the arm conduction status information. Combining this with a preset correspondence between arm conduction status, phase current, and arm current, the current of the currently conducting arm is calculated. This scheme indirectly obtains the arm current of the hybrid commutator valve by measuring the phase current at the AC inlet and analyzing the arm conduction status information. It eliminates the need for current sensors on the arms, is unaffected by electromagnetic interference or vibration, and ensures the accuracy of the acquired arm current. Thus, using the highly accurate arm current to achieve active shutdown monitoring of the hybrid commutator valve effectively improves its operational reliability.

[0057] Please see Figure 3 In one embodiment, the hybrid commutation valve operation method further includes steps 302 and 304.

[0058] Step 302: Obtain the DC current measurement value at the DC inlet of the hybrid commutation valve.

[0059] Step 304: Based on the measured DC current and phase current values, perform fault detection on the hybrid commutation valve.

[0060] Specifically, in the DC input port, i.e., in the hybrid commutation converter valve, the bridge arm power unit is used to connect to the DC side line port. In one embodiment, since there are two lines used by the bridge arm power unit to connect to the DC side, a DC current acquisition device needs to be set up at each line port to send the acquired current sampling value to the control device, which then analyzes the data to obtain the DC current measurement value.

[0061] It is understood that, similar to the phase current acquisition device in the above embodiment, each DC current acquisition device can acquire multiple current sampling values. After receiving multiple current sampling values, the control device performs optimization analysis and finally determines the DC current measurement value corresponding to each DC input port.

[0062] After obtaining the DC current measurement value, the control device combines it with the phase current measurement value to perform fault analysis, detecting whether the hybrid commutation converter valve is malfunctioning and, if so, the specific type of fault. This allows for timely detection of any malfunctions in the hybrid commutation converter valve, further improving its operational reliability.

[0063] It should be noted that the faults of the mixed-phase converter valve include, but are not limited to, grounding faults and short-circuit faults. Taking the 12-pulse converter valve as an example, grounding faults may include at least one of the following: 12-pulse neutral point grounding fault, DC side grounding fault, high-voltage bridge (D-bridge) neutral point grounding fault, and low-voltage bridge (Y-bridge) neutral point grounding fault. Short-circuit faults may include at least one of the following: high-voltage bridge arm short-circuit fault, low-voltage bridge arm short-circuit fault, simultaneous short-circuit fault of high-voltage and low-voltage bridge arms, high-voltage bridge phase-to-phase short circuit or three-phase short circuit, low-voltage bridge phase-to-phase short circuit or three-phase short circuit, DC side short circuit, high-voltage bridge upper and lower arm short circuit, and low-voltage bridge upper and lower arm short circuit. The specific faults are not limited.

[0064] Please see Figure 4 In one embodiment, the DC current measurement value includes the DC current measurement value of the first terminal and the DC current measurement value of the second terminal, and the phase current measurement value includes the Y-bridge phase current measurement value and the D-bridge phase current measurement value; step 304 includes steps 402, 404 and 406.

[0065] Step 402: Determine the maximum value of the first phase current based on the absolute value of the measured phase current of the D-bridge.

[0066] Step 404: Determine the maximum value of the second phase current based on the absolute value of the measured Y-bridge phase current.

[0067] Step 406: Based on the maximum value of the first phase current, the maximum value of the second phase current, the measured value of the first terminal DC current, and the measured value of the second terminal DC current, perform fault detection on the hybrid commutation valve.

[0068] Specifically, this embodiment uses a 12-pulse converter valve for explanation. The Y-bridge phase current measurement value is the three phase current measurement value corresponding to the Y-bridge of the hybrid commutation converter valve, and the D-bridge phase current measurement value is the three phase current measurement value corresponding to the D-bridge of the hybrid commutation converter valve. As shown in the above embodiment, there are two lines used by the bridge arm power unit to connect to the DC side. Therefore, by measuring each line, the first-end DC current measurement value and the second-end DC current measurement value can be obtained respectively. After that, the control device analyzes the D-bridge phase current measurements and takes the maximum absolute value of the three D-bridge phase current measurements as the first phase current maximum value; it also analyzes the Y-bridge phase current measurements and takes the maximum absolute value of the three Y-bridge phase current measurements as the second phase current maximum value. Combining the first phase current maximum value, the second phase current maximum value, the first-end DC current measurement value, and the second-end DC current measurement value, the hybrid commutation converter valve is used for fault detection.

[0069] The above scheme, which combines the absolute maximum values ​​of the D-bridge phase current measurement and the Y-bridge phase current measurement, is used to detect faults in the hybrid commutation valve, and has high fault detection accuracy.

[0070] It is understood that in other embodiments, fault detection can be performed in other ways, such as comparing the magnitude of the DC current measurement value with the phase current measurement value, or comparing the magnitude of the Y-bridge phase current measurement with the D-bridge phase current measurement, etc., without being limited to any specific method.

[0071] Please see Figure 5 In one embodiment, step 406 includes steps 502, 504, 506 and 508.

[0072] Step 502: Determine the first criterion condition based on the maximum value of the first phase current, the measured value of the first terminal DC current, and the set value of the starting current.

[0073] Step 504: Determine the second criterion condition based on the maximum value of the first phase current, the maximum value of the second phase current, and the set value of the starting current.

[0074] Step 506: Determine the third criterion condition based on the maximum value of the second phase current, the measured value of the second terminal DC current, and the set value of the starting current.

[0075] Step 508: Perform fault detection on the hybrid commutation valve according to the first criterion condition, the second criterion condition, and the third criterion condition.

[0076] Specifically, the starting current setting value is a specific set value of the current required by the converter valve during the startup process in a high-voltage direct current transmission system. It can generally be set to 0.1 pu (per-unit value, which can be understood as using the rated current of the hybrid commutation converter valve as a reference) - 0.2 pu. In this embodiment, the scheme combines the maximum value of the first phase current, the measured value of the first terminal DC current, and the starting current setting value to establish a first criterion condition for fault detection of the hybrid commutation converter valve. Combining the maximum value of the first phase current, the maximum value of the second phase current, and the starting current setting value, a second criterion condition is established for fault detection of the hybrid commutation converter valve. Combining the maximum value of the second phase current, the measured value of the second terminal DC current, and the starting current setting value, a third criterion condition is established for fault detection of the hybrid commutation converter valve.

[0077] After that, the maximum value of the first phase current, the maximum value of the second phase current, the measured value of the first terminal DC current, and the measured value of the second terminal DC current are obtained in real time and substituted into three criteria conditions for judgment and analysis. The final analysis results are used to realize the fault detection of the hybrid commutation valve.

[0078] The above scheme, which combines the three established criteria for fault detection of hybrid commutation valves, has high detection convenience.

[0079] Please see Figure 6 In one embodiment, step 508 includes step 602.

[0080] Step 602: Determine the fault state of the hybrid commutation valve based on the number of triggering criteria and the triggering method in the first, second, and third criteria conditions.

[0081] Specifically, criterion triggering means meeting the set criterion conditions. Specifically, if the maximum value of the first phase current and the measured value of the first terminal DC current both meet the set first criterion condition, the first criterion condition is triggered; if the maximum value of the first phase current and the maximum value of the second phase current both meet the set second criterion condition, the second criterion condition is triggered; and if the maximum value of the second phase current and the measured value of the second terminal DC current both meet the set third criterion condition, the third criterion condition is triggered. The number of triggering criteria refers to the number of criteria among the first, second, and third criterion conditions that are triggered, which can be one, two, or three. The triggering method refers to the way different criterion conditions are triggered, including but not limited to alternating triggering and simultaneous triggering, etc., and is not specifically limited.

[0082] Further, in one embodiment, step 602 includes: when the number of triggering criteria among the first criterion condition, the second criterion condition, and the third criterion condition is one in a cycle, determining the ground fault type of the hybrid commutator valve according to the criterion triggering method; when the number of triggering criteria among the first criterion condition, the second criterion condition, and the third criterion condition is two in a cycle, determining the short circuit fault type of the hybrid commutator valve according to the criterion triggering method.

[0083] In this embodiment, the fault types of the hybrid commutator valve include ground faults and short-circuit faults. If, within one cycle, the number of triggers of the above three criteria conditions in the hybrid commutator valve is one, the ground fault type is determined based on the specific triggering method. If, within one cycle, the number of triggers of the above three criteria conditions in the hybrid commutator valve is two, the short-circuit fault type is determined based on the specific triggering method. Thus, by analyzing different fault types based on different numbers of triggers of the criteria conditions, the accuracy of fault analysis is improved.

[0084] To facilitate understanding of the technical solution of this application, the following embodiments also use a 12-pulse converter valve for explanation. First, when the number of criterion triggers is 0 within the same cycle, it indicates that the mixed-phase converter valve has not malfunctioned. When the number of criterion triggers is three, that is, when the first criterion condition, the second criterion condition, and the third criterion condition are triggered simultaneously within the same cycle, it is determined that multiple faults are superimposed.

[0085] When the number of criterion triggers is one in a cycle, the following situations apply: (1) The second criterion condition is triggered alone, and the fault is judged as a twelve-pulse neutral point grounding fault; (2) The first criterion condition is triggered alone, and the fault is judged as a DC side grounding fault; (3) The first criterion condition and the second criterion condition are triggered alternately, and the fault is judged as a high-voltage bridge (D-bridge) neutral point grounding fault; (4) The second criterion condition and the third criterion condition are triggered alternately, and the fault is judged as a low-voltage bridge (Y-bridge) neutral point grounding fault.

[0086] When there are two triggers of the criteria within a cycle, the following situations apply: (1) The first and second criteria are triggered in the same half-cycle, but not in the other half-cycle. In this case, it is judged as a short circuit fault in the high-voltage bridge arm; (2) The second and third criteria are triggered in the same half-cycle, but not in the other half-cycle. In this case, it is judged as a short circuit fault in the low-voltage bridge arm; (3) The first, second, and third criteria are all triggered in the same cycle, and only two criteria are triggered at the same time. In this case, it is judged as a short circuit fault in both the high-voltage and low-voltage bridge arms; (4) The first and second criteria are triggered at the same time in the same cycle, and the current (output current of the mixed commutation valve) increases to (5) If the preset current threshold (e.g., 2pu) is above, it is judged as a phase-to-phase short circuit or a three-phase short circuit of the high-voltage bridge; (6) If the second criterion condition and the third criterion condition are triggered simultaneously in the same cycle, and the current increases to more than 2pu, it is judged as a phase-to-phase short circuit or a three-phase short circuit of the low-voltage bridge; (7) If the first criterion condition and the third criterion condition are triggered simultaneously in the same cycle, it is judged as a DC side short circuit fault; (8) If the first criterion condition and the second criterion condition are triggered simultaneously in the same cycle, and the current is below 2pu, it is judged as a short circuit fault of the upper and lower arms of the high-voltage bridge; (9) If the second criterion condition and the third criterion condition are triggered simultaneously in the same cycle, and the current is below 2pu, it is judged as a short circuit fault of the upper and lower arms of the low-voltage bridge.

[0087] In one embodiment, the hybrid commutator valve operation method includes at least one of the following: a first criterion condition including: the absolute value of the difference between the maximum value of the first phase current and the measured value of the first terminal DC current is greater than a set value of the starting current; a second criterion condition including: the absolute value of the difference between the maximum value of the first phase current and the maximum value of the second phase current is greater than the set value of the starting current; and a third criterion condition including: the absolute value of the difference between the maximum value of the second phase current and the measured value of the second terminal DC current is greater than the set value of the starting current.

[0088] Specifically, the types of the first, second, and third criterion conditions are not unique; any type that can reasonably characterize the fault state of the hybrid commutator valve is acceptable. In this embodiment, the absolute value of the difference between the maximum value of the first phase current and the measured value of the first-terminal DC current is greater than the set starting current value, which is determined as the first criterion condition. That is... ,in, This indicates the measured value of the DC current at the first terminal. This indicates the maximum value of the first phase current. This represents the set value of the starting current; correspondingly, if this relationship holds, the first criterion is considered to be triggered.

[0089] The absolute value of the difference between the maximum value of the first-phase current and the maximum value of the second-phase current, which is greater than the set starting current value, is determined as the second criterion. That is... ,in, This represents the maximum value of the second phase current; correspondingly, if this relationship holds, the second criterion is considered to be triggered.

[0090] The absolute value of the difference between the maximum value of the second-phase current and the measured value of the DC current at the second terminal is greater than the set value of the starting current, which is determined as the third criterion condition. That is... ,in, This represents the measured DC current value at the second terminal; correspondingly, if this relationship holds, the third criterion is considered to be triggered.

[0091] Please see Figure 7 In one embodiment, step 104 includes steps 702 and 704.

[0092] Step 702: Receive the current sampling value collected and sent by the phase current acquisition device located at the AC inlet of the hybrid commutation valve.

[0093] Step 704: Perform optimization analysis based on each current sampling value to determine the phase current measurement value of the AC inlet.

[0094] Specifically, one phase current acquisition device is installed for each AC input port. Each phase current acquisition device includes at least two fiber optic current transformers, and each fiber optic current transformer acquires a current sample value. The phase current measurement value corresponding to each AC input port is acquired separately, that is, each AC input port is equipped with a separate phase current acquisition device. Within the same phase current acquisition device, multiple fiber optic current transformers (CTs) are installed, and each fiber optic current transformer can independently sample to obtain a current sample value. This not only achieves redundancy in the sampling function of the phase current acquisition device, but also allows for the optimization of multiple current sample values ​​to obtain a more accurate phase current measurement value.

[0095] It is understandable that the phase current acquisition device samples in real time at a certain sampling period during the operation of the hybrid commutation valve. Specifically, a sampling period of 4μs (microseconds) is acceptable, but the specific period is not limited and can be set according to actual needs. The DC current acquisition device installed at the DC input port has the same structure and sampling principle as the phase current acquisition device, and will not be described in detail here.

[0096] It should be noted that the number of fiber optic current transformers in the same phase current acquisition device is not unique. In one embodiment, it may include three, four, five or even more fiber optic current transformers. For ease of understanding of the technical solution of this application, the following embodiments can all be understood as including four fiber optic current transformers.

[0097] The method by which the control device performs optimal analysis based on each current sampling value is not unique. In one embodiment, it may combine each current sampling value to calculate the phase current measurement value. In another embodiment, it may assign one of the current sampling values ​​as the phase current measurement value; the specific method is not limited.

[0098] The specific structure of the control device is not unique. In one embodiment, the control device includes a valve controller and a redundant first and second active shutdown judgment chassis. Each phase current acquisition device is connected to both the first and second active shutdown judgment chassis. The active shutdown judgment chassis performs optimal analysis on the sampled current values ​​to obtain the phase current measurement values ​​before sending them to the valve controller. This not only alleviates the data processing pressure but also improves the operational reliability of the control device through the redundancy of the active shutdown judgment chassis.

[0099] Please see Figure 8 In one embodiment, step 704 includes steps 802 and 804.

[0100] Step 802: Check whether any current sampling values ​​are abnormal.

[0101] Step 804: If at least two current sampling values ​​are normal, determine the phase current measurement value of the AC input port based on the normal current sampling values.

[0102] Specifically, when the control device performs optimization based on current sampling values, it first needs to verify whether each current sampling value is abnormal. If at least two current sampling values ​​are normal, optimization can be performed based on the normal current sampling values ​​to determine the phase current measurement value of the AC input port. However, if there are not two normal current sampling values, it may be that all current sampling values ​​are abnormal. In this case, the currently collected current sampling value is considered meaningless, and an abnormality prompt message is output. Alternatively, it may be that only one current sampling value is normal. In this case, optimization cannot be performed, and an abnormality prompt message is also output.

[0103] The above scheme requires that each current sampling value be verified first when obtaining the current sampling value, and the phase current measurement value is determined based on the verification result, so as to further improve the accuracy of the phase current measurement value.

[0104] It should be noted that there is no single way to check whether any current sample value is abnormal. In one embodiment, it can be achieved by determining whether the absolute value of the difference between any two current sample values ​​is within the allowable measurement error range.

[0105] Specifically, taking four current sampling values ​​as an example, with the ratios I1, I2, I3, and I4, let A1 = |I1-I2|, A2 = |I1-I3|, A3 = |I1-I4|, A4 = |I2-I3|, A5 = |I2-I4|, and A6 = |I3-I4|. We define A1, A2, A3, A4, A5, and A6 as: less than or equal to the measurement error (e.g., 25 amperes) is normal; and A1, A2, A3, A4, A5, and A6 as: greater than the measurement error is abnormal. The following table can be used to analyze whether each current sampling value is normal:

[0106]

[0107] Taking three current sampling values ​​as an example, with the ratios I1, I2, and I3, let A1 = |I1 - I2|, A2 = |I1 - I3|, and A3 = |I2 - I3|. We define A1, A2, and A3 as being less than or equal to the measurement error (normal) and A1, A2, and A3 as being greater than the measurement error (abnormal). The following table can be used to analyze whether each current sampling value is normal:

[0108]

[0109] Furthermore, taking two current sampling values ​​as an example, with the ratio of the two current sampling values ​​being I1 and I2, let A1 = |I1 - I2|. Correspondingly, if the analysis shows that A1 is normal, that is, A1 is less than or equal to the measurement error, it is determined that both current sampling values ​​are normal at this time; if the analysis shows that A1 is abnormal, that is, A1 is greater than the measurement error, it is determined that both current sampling values ​​are abnormal at this time.

[0110] Please see Figure 9 In one embodiment, step 804 includes steps 902 and 904.

[0111] Step 902: If both current sampling values ​​are normal, the average of the two normal current sampling values ​​is taken as the phase current measurement value of the AC input port.

[0112] Step 904: If three or more current sampling values ​​are normal, determine the average value of the normal current sampling values, and take the normal current sampling value with the smallest absolute value of the difference from the average value as the phase current measurement value of the AC input port.

[0113] Specifically, in this embodiment, when two current sampling values ​​are normal, the average value is used as the phase current measurement value of the AC input port; when three or more current sampling values ​​are normal, the data closest to the average of the normal current sampling values ​​is used as the phase current measurement value of the AC input port. Thus, by using different methods to analyze and obtain the phase current measurement value according to the number of normal current sampling values, the accuracy of the phase current measurement value can be further improved.

[0114] Please see Figure 10 In one embodiment, prior to step 702, the method further includes steps 1002 and 1004.

[0115] Step 1002: Obtain the operating status of each fiber optic current transformer in the phase current acquisition device.

[0116] If at least two fiber optic current transformers are functioning normally, proceed to step 702.

[0117] Step 1004: If all fiber optic current transformers are abnormal or one fiber optic current transformer is normal, output a message prohibiting active shutdown.

[0118] Specifically, the number of current sampling values ​​that the phase current acquisition device can obtain is not only related to the number of fiber optic current transformers configured in the phase current acquisition device, but also directly related to the operating status of each fiber optic current transformer. If a fiber optic current transformer fails, the corresponding number of output current sampling values ​​will also decrease.

[0119] Therefore, to ensure the subsequent optimization of current sample values, the scheme in this embodiment requires that at least two fiber optic current transformers in the same phase current acquisition device be in normal operating condition. This means acquiring the operating status of each fiber optic current transformer and performing fault detection on each transformer. If all fiber optic current transformers are malfunctioning or only one is functioning normally, a "prohibit active shutdown" message is output, causing the hybrid commutation valve to stop actively shutting down, thus reducing the risk of further faults caused by active shutdown.

[0120] It should be noted that there is no single way to determine whether each fiber optic current transformer in the phase current acquisition device is abnormal. In one embodiment, it may be to obtain identification information that characterizes the operating status of the fiber optic current transformer. If the status of the fiber optic current transformer is received as "no good" for a certain period of time (e.g., 500 μs, corresponding to 125 sampling periods) or for a certain number of consecutive times, the fiber optic current transformer is considered to be abnormal.

[0121] In another embodiment, this can also be achieved by analyzing the current sampling values ​​of the fiber optic current transformer. For example, if a fiber optic current transformer consistently determines that the deviation between its current sampling value and the current sampling values ​​of other fiber optic current transformers exceeds the measurement error for 25,000 consecutive times (100ms, 4μs each time), then that fiber optic current transformer is set as abnormal.

[0122] Please refer to the following: Figure 2 This application embodiment also provides a hybrid commutation converter valve, including a bridge arm power unit 20, a phase current acquisition device 21, and a control device (not shown). The phase current acquisition device 21 is disposed at the AC inlet of the bridge arm power unit 20. The phase current acquisition device 21 and the bridge arm power unit 20 are respectively connected to the control device. The control device is used to execute the steps of the above-described hybrid commutation converter valve operation method.

[0123] Specifically, the operation method of the hybrid commutation converter valve is as shown in the above embodiments and accompanying drawings, and will not be repeated here. The hybrid commutation converter valve obtains the phase current measurement value at the AC inlet of the valve and the arm conduction status information, and combines this with a preset correspondence between arm conduction status, phase current, and arm current to analyze and calculate the arm current of the currently conducting arm. This scheme indirectly obtains the arm current of the hybrid commutation converter valve by measuring the phase current measurement value at the AC inlet of the valve and analyzing it in conjunction with the arm conduction status information. It eliminates the need to install current sensors on the arms of the valve, is unaffected by electromagnetic interference or vibration, and ensures the accuracy of the obtained arm current. Thus, by using a highly accurate arm current to achieve active shutdown monitoring of the hybrid commutation converter valve, the operational reliability of the valve is effectively improved.

[0124] Please refer to the following: Figure 11 In one embodiment, a DC current acquisition device 22 is also provided at the DC input port of the bridge arm power unit 20, and the DC current acquisition device 22 is connected to the control device.

[0125] Specifically, since the bridge arm power unit 20 has two lines for connecting to the DC side, a DC current acquisition device 22 needs to be set at the port of each line to send the acquired current sampling value to the control device, and the control device analyzes the data to obtain the DC current measurement value.

[0126] After obtaining the DC current measurement value, the control device combines the phase current measurement value to perform fault analysis, detect whether the hybrid commutation valve is malfunctioning, and the specific type of fault. In this way, it can promptly detect when the hybrid commutation valve malfunctions, further improving the operational reliability of the hybrid commutation valve.

[0127] In one embodiment, the phase current acquisition device 21 and the DC current acquisition device 22 have the same structure, both including at least two fiber optic current transformers.

[0128] Specifically, multiple fiber optic current transformers are installed in the same phase current acquisition device 21 or DC current acquisition device 22. Each fiber optic current transformer can independently sample to obtain a current sample value. In this way, not only can the sampling function be redundant, but multiple current sample values ​​can also be combined for optimization to obtain a more accurate phase current measurement value or DC current measurement value.

[0129] In one embodiment, the control device includes a valve controller and a first active shutdown judgment box and a second active shutdown judgment box that are redundant with each other. The phase current acquisition device 21 is connected to the first active shutdown judgment box and the second active shutdown judgment box respectively. The first active shutdown judgment box and the second active shutdown judgment box are respectively connected to the valve controller.

[0130] Specifically, each phase current acquisition device 21 is connected to both the first and second active shutdown judgment chassis. The active shutdown judgment chassis performs optimal analysis on the sampled current values ​​to obtain the phase current measurement values ​​before sending them to the valve controller. This not only alleviates the data processing pressure but also improves the operational reliability of the control device through the redundancy of the active shutdown judgment chassis.

[0131] In the description of this specification, references to terms such as "some embodiments," "other embodiments," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative descriptions of the above terms do not necessarily refer to the same embodiments or examples.

[0132] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0133] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A method for operating a hybrid commutation converter valve, characterized in that, include: Obtain the bridge arm conduction status information of the hybrid commutation valve; Obtain the phase current measurement value at the AC inlet of the hybrid commutator valve; Based on the bridge arm conduction status information, the phase current measurement value, and the preset correspondence between bridge arm conduction status, phase current, and bridge arm current, the bridge arm current of the currently conducting bridge arm is determined; wherein, the bridge arm current is used to actively monitor the shutdown of the hybrid commutation valve.

2. The method for operating a hybrid commutation valve according to claim 1, characterized in that, Also includes: Obtain the DC current measurement value at the DC inlet of the hybrid commutation valve; The hybrid commutation valve is fault detected based on the measured DC current and the measured phase current.

3. The method for operating a hybrid commutation valve according to claim 2, characterized in that, The DC current measurement values ​​include the DC current measurement values ​​at the first terminal and the DC current measurement values ​​at the second terminal, and the phase current measurement values ​​include the Y-bridge phase current measurement values ​​and the D-bridge phase current measurement values; The step of fault detection of the hybrid commutation valve based on the measured DC current value and the measured phase current value includes: The maximum value of the first phase current is determined based on the absolute value of the measured phase current of the D-bridge. The maximum value of the second phase current is determined based on the absolute value of the measured Y-bridge phase current. The hybrid commutation valve is fault detected based on the maximum value of the first phase current, the maximum value of the second phase current, the measured value of the DC current at the first end, and the measured value of the DC current at the second end.

4. The method for operating the hybrid commutation valve according to claim 3, characterized in that, The fault detection of the hybrid commutation valve based on the maximum value of the first phase current, the maximum value of the second phase current, the measured value of the DC current at the first terminal, and the measured value of the DC current at the second terminal includes: The first criterion condition is determined based on the maximum value of the first phase current, the measured value of the first terminal DC current, and the set value of the starting current; The second criterion condition is determined based on the maximum value of the first phase current, the maximum value of the second phase current, and the set value of the starting current; The third criterion condition is determined based on the maximum value of the second phase current, the measured value of the second terminal DC current, and the set value of the starting current; The hybrid commutation valve is fault detected based on the first criterion, the second criterion, and the third criterion.

5. The method for operating the hybrid commutation valve according to claim 4, characterized in that, The fault detection of the hybrid commutation valve based on the first criterion, the second criterion, and the third criterion includes: The fault state of the hybrid commutation valve is determined based on the number of triggering criteria and the triggering method in the first, second, and third criteria conditions.

6. The method for operating a hybrid commutation valve according to claim 5, characterized in that, The step of determining the fault state of the hybrid commutation valve based on the number of triggering criteria and the triggering method among the first, second, and third criteria includes: Within one cycle, if the number of triggering criteria among the first criterion, the second criterion, and the third criterion is one, the ground fault type of the hybrid commutation valve is determined according to the criterion triggering method. Within a cycle, if there are two triggering criteria among the first criterion, the second criterion, and the third criterion, the short-circuit fault type of the hybrid commutation valve is determined according to the criterion triggering method.

7. The method for operating a hybrid commutation valve according to claim 4, characterized in that, Includes at least one of the following: The first criterion includes: the absolute value of the difference between the maximum value of the first phase current and the measured value of the first terminal DC current is greater than the set value of the starting current; The second criterion includes: the absolute value of the difference between the maximum value of the first phase current and the maximum value of the second phase current is greater than the set value of the starting current; The third criterion includes: the absolute value of the difference between the maximum value of the second phase current and the measured value of the second terminal DC current is greater than the set value of the starting current.

8. The method for operating the hybrid commutation converter valve according to any one of claims 1-7, characterized in that, The step of obtaining the phase current measurement value at the AC inlet of the hybrid commutator valve includes: The current sampling value is received by the phase current acquisition device set at the AC inlet of the hybrid phase-commutation valve; wherein, one phase current acquisition device is set for each AC inlet, each phase current acquisition device includes at least two fiber optic current transformers, and each fiber optic current transformer acquires a current sampling value. Based on the current sampling values, the phase current measurement value of the AC inlet is determined through optimization analysis.

9. The method for operating a hybrid commutation valve according to claim 8, characterized in that, The step of performing optimization analysis based on the current sampling value to determine the phase current measurement value of the AC input port includes: Verify whether any of the current sampling values ​​are abnormal; If at least two of the current sampling values ​​are normal, the phase current measurement value of the AC input port is determined based on the normal current sampling values.

10. The method for operating a hybrid commutation converter valve according to claim 9, characterized in that, The step of determining the phase current measurement value of the AC input port based on the normal current sampling values ​​when at least two of the current sampling values ​​are normal includes: If both current sampling values ​​are normal, the average of the two normal current sampling values ​​shall be taken as the phase current measurement value of the AC input port. If three or more current sampling values ​​are normal, the average value of the normal current sampling values ​​is determined, and the normal current sampling value with the smallest absolute difference from the average value is taken as the phase current measurement value of the AC input port.

11. The method for operating a hybrid commutation valve according to claim 8, characterized in that, Before receiving the current sampling value collected and transmitted by the phase current acquisition device located at the AC inlet of the hybrid commutator valve, the method further includes: Obtain the operating status of each fiber optic current transformer in the phase current acquisition device; When at least two of the fiber optic current transformers are functioning normally, the step of receiving the current sample value collected and transmitted by the phase current acquisition device located at the AC inlet of the hybrid commutation valve is performed. If all of the fiber optic current transformers are malfunctioning or one of the fiber optic current transformers is functioning normally, an active shutdown warning message will be output.

12. A hybrid commutation valve, characterized in that, The device includes a bridge arm power unit, a phase current acquisition device, and a control device. The phase current acquisition device is located at the AC input port of the bridge arm power unit. The phase current acquisition device and the bridge arm power unit are respectively connected to the control device. The control device is used to execute the steps of the hybrid commutation valve operation method according to any one of claims 1-11.

13. The hybrid commutation valve according to claim 12, characterized in that, It also includes a DC current acquisition device located at the DC input port of the bridge arm power unit, and the DC current acquisition device is connected to the control device.

14. The hybrid commutation valve according to claim 13, characterized in that, The phase current acquisition device and the DC current acquisition device have the same structure, both including at least two fiber optic current transformers.

15. The hybrid commutation valve according to claim 12, characterized in that, The control device includes a valve controller, and a first active shutdown judgment box and a second active shutdown judgment box that are redundant with each other. The phase current acquisition device is connected to the first active shutdown judgment box and the second active shutdown judgment box respectively. The first active shutdown judgment box and the second active shutdown judgment box are respectively connected to the valve controller.

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